Electrode holder for spectrographic analysis



April 11, 1944 B. F. scRlBNl-:R Erm. 2,346,512

ELECTRODE HOLDER FOR SPECTROGRAPHIC ANALYSIS Filed April 21. 1943 4 Sheets-Sheet 1 CHA/afs #avm/@ 60H55 @Y `umf ATToRNEY April 11, 1944. B. F. scRlBNER :s1-AL ELECTRODE HOLDER FOR SPECTROGRAPHIC ANALYSIS 4 Sheets-Sheet 2 Filed April 21, 1943 l R l.,

I vf INVENToRs Q -1* i fmQ/vc/sc/BNER CHA/e155 Hmm/Y0 Corel/55 @Y A 1M/MM ATTORNEY April ll, 1944.

B. F. scRlBNER Erm. 2,346,512 ELECTRODE HOLDER FOR SPECTROGRAPHIC ANALYSIS I Filed April 21. 194s 4 sheets-sheet s I Y n 4 32 .glll'. .Q 30 27 ,Sr v A A 2' L//////// l /Z INVENTORS CHAR/ E5 HOWARD CURL/65 5y ATTORNEY April 11, 1944. B. F. scRlBNER ETAL ELECTRODE HOLDER FOR SPECTROGRAPHIC ANALYSIS Filed April 2l, 1943 4 Sheets-Sheet 4 l- 9W J Cv\\\* 0 T 6 Z o Luz 9 6. e Ivm. o 95 'WM .6

lNvENToRs Boz/Roan FPANc/s 56E/BME@ 0 CHAR/ E5 Haw/seo (JOEL/S5 ATTORNEY Patented pr. il, 1944 ELECTRODE HOLDER FOR SPECTRO- GRAPHIC ANALYSIS Bourdon Francis Scribner, Washington, D. C., and

Charles Howard Corliss, Medi'ord, Mass., asaknors to the Government o! the United States, as represented by the Secretary of the Department of Commerce AipplicatlonAAprll 21, 1943, Serial No. 483,974

9 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government of the United States for governmental purposes without the payment to us of any royalty thereon in accordance with the provisions of the act of April 30, 1928 (Ch. 460, 45 Stat. L. 467).

Our invention relates to an improved electrode holder for spectrographic analysis having means for accurately spacing and accurately aligning electrodes. f

Our invention includes a protecting shield for safeguarding operators from injury from high voltage shocks and from injurious rays, particularly ultra violet, which may cause cumulative injury, as to the eyes.

Our invention further provides means yfor clamping electrodes of assorted sizes as wellv as thin sheet metal and rigid bars, including means for quickly renewing or interchanging electrodes.

This invention has been described in the illusl trated Research Paper R.. P. 1515, National Bureau oi Standards, U. S. Department of Commerce. l

In the accompanying drawings:

Figure l is an elevation of our device, the door being open to the full line position shown in Figure 2, partly in section.

Figure 2 is a plan view of the housing showing two open positions of the door, partly in section. Figure 3 is a section on the line 3 3, Figure 1.

Fiure 4 is a detail section on the line 44, Figure 3.

yFigure 5 is a detail section on the line 5 5, 'Figure 3.

Figure 6 is a detail section on the line 6 6, Figure 3.

Figure is a detail side elevation of our electrode clamps, enlarged, looking in the direction ofthe ine 1-1, of Figure 1.

Figure'S is a detail plan view of one of our electrode clamps, partly in section.

Figure 9 is a detail enlarged elevation of an accessory clamp for holding sheet samples, mounted in our main lever clamp.

Figure 10 is a side elevation of our accessory clamp shown in Figure 9.

Figure 11 is detail of a yielding door stop.

In these drawings, 2i represents a base. prefery 2l and clamped against amber 26 oi the optical bench by a thraaed bolt having' a 1mm-led head 28.

On the base 2| is mounted a slide 30 which is dove-tailed thereto, see Figs. 3 and 4. This slide 30 is moved laterally by a nut and screw, the latter having an operating handle 3l, see Figure 5. The slide carries two rigidly attached rods 32, which guide a pair of electrode supports 33. Each support is H-shapedwith a rigid bar 34 joining two relatively long sleeves 35 which slide on the rods 32. To each bar 34 is bolted an insulating Bakelite plate 36 which rigidly supports an electrode clamp 31. lThe rods 32 are braced at their upper ends by a plate 38 which also provides a bearing for a screw 39 threaded into the bar 34. For convenience, the screw 39 is manually operated byY a handle 4l! through mitre gears and a laterally extending shaft. To the screw 39 there is rigidly connected a graduated drum 4l under the plate 38. The companion electrode support is vertically adjusted by a screw 42 and operating handle 43 which correspond to the upper control assembly, except that the graduatedy drum is omitted.

The electrode clamps are shown in detail in Figures 7 and 8, in which a xed jaw 44 is bolted to the Bakelite plate 36. The jaw 44 is provided with atube 45 for the passage of cooling liquid, a pair oilateral guide grooves for a companion jaw 46 and a transverse passage for an eccentric 41 mounted in the jaw 46 and a plurality of vertical, semi-circular grooves 46; 49; 56 and 5I ot different radii which are aligned with corresponding grooves in the movable jaw and may also vary in size between the bottom and the top to allow for 'tting commercial electrodes and for avoiding strains in electrodes which are not absolutely straight.

in the iixed jaw 44 and two rigidly attached bars- 53 which slide in the lateral grooves of the xed jaw. The bars 53 also provide bearings for the eccentric 41 and are joined by a somewhat U- shaped member 54 which serves as a housing for a. compression spring 65, which pulls the jaw 46 against the ii-xed jaw 44. These clamps are provided with binding posts 66 for connection with a source of electric power, 'an inner cover plate 51, see' Figures and 8, and an outer cover plate 58, each of which is bolted to the iixed jaw and serve to complete a housing for the eccentric 41 and the spring 56.

Figure '7 is an enlarged side elevation showingn carbon electrode 59 and a lower two-part elecv trode lill having a replaceable cup-like terminal 6i provided with a recess for holding a specimen to be tested. This two-part form of electrode makes possible a saving in cost because the terminal portion is usually made of relatively expensive carbon.

For using samplesvin sheetl or bar form we provide an accessory clamp 62, see Figures 9, 10, with attaching studs, such as indicated by 53, which fit in corresponding holes in one of ou;` clamping jaws. This clamp has two inwardly extending flanges 64 and d5 and a hinged jaw 66 manually adjusted by means of a screw having a knurled head 6l working in a pressure transmitting nut 68. This clamp will accommodate both relatively thick samples or thin sheet samples, in the latter case a rigid backing block 69 of copper or the like transmits clamping pressure to the margins of the sheet such as lu.

To accommodate electrodes or cylindrical specimens which do not nt in any of the holes of our electrode clamps we use split copper bushings, not shown, externally machined to t holes incur clamps.

A housing 'li for our holder is built on a frame of angle iron, covered with sheet metal. The door 12 of the housing is the forward half of the housing and serves to Aoperate a safety circuit breaker 13 in the high voltage power circuit and also closes a second switch 'ld to a lamp 'l5 in a corner of the door. This door may be opened for renewing electrodes or samples to the dot and dash position indicated in Figure 2, in which position the lamp illuminates the clamps and other parts, though shielded from the eyes of the operator. There is also a bar 'lli pivoted at ll to a cross-frame located in the housing and a spring controlled plungerl which engages a notch in the bar 1B which serves as a stop to'position the lamp and electrodes in alignment with an opening 19 in the rear of the casing for projecting an image of the electrodes on a screen, not shown, on the optical path to facilitate the adjustment of the electrode positions. There is also an opening 80 in the face of the door through which, when the door is closed, passes the optical path to a spectrograph, not shown. Our housing serves to safeguard the operator by protecting his eyes from ultra-violet rays because the circuit to the electrode is opened whenever the dooris even partly open; secondly, from accidental electric Vshock because no voltage is supplied to the electrode clamps while the door is open; and, thirdly, by carrying off through the hood any noxious gases formed in the arc. g

The operation of our device is as follows: With the door opened to the dot and dash position, Figure 2, our electrode clamps are illuminated from the electric light l in the door, the lower one of our electrode clamps is opened by turningthe handle of the eccentric 41, an electrode containing a specimen to be analyzed is inserted in one ofthe holes of the clamp and the eccentric is again turned ninety degrees (90) to release the jaws to clamp the electrode. The same procedure may be followed for lowering an electrode through the upper clamp. The door is then closed to the intermediate stop andwith the aid of a lens and a screen, not shown, an image of the electrodes is projected on the screen and by turning the handle 3l the image is centered between the vertical edges of the screen. The image is then centered vertically by turning the cranks 40 and 43. The electrodes are then separated bya predetermined distance by turning the crank d 'and counting the revolutions and fractions of a revolution of the attached drum tl. The entire structure may be adjusted along `the rails 2A and 25 by releas f5A ing the claw-like members 2S by means of the knurled head. 29, or if desired, this member 2S may be further released and the whole device may be removed from the optical bench.

The door is then closed, which automatically turns oil the current'to the lamp l5 and closes the safety circuit permitting completion of the high voltage circuit through the electrode, producing light which passes through the hole in the door to a slit in the spectrograph assembly, not illustrated.

The foregoing description of our preferred form of our invention is not intended to restrict our claims to that form, but We claim the inventions herein disclosed without any limitations other than those of the claims which may be allowed.

What we claim. is:

l. An electrode clamp comprising a movable jaw provided with two rigidily attached bars and a passage for cooling uid, a fixed jaw provided with a groove for each of said bars and also provided with a passage for cooling iluid resilient means for closing. said jaws, and manually operated means for opening said jaws in opposition to said resilient closing means.

2. In a precision-acting electrode holder for rapid spectrographic analysis, an electrode clamp comprising two water-cooled jaws having a plurality of electrode-engaging openings to lit closely electrodes of several standard sizes and pro- 35 vided with manually operated resilient means for quickly clamping and releasing an electrode.

3. In a precision-acting electrode holder for rapid spectrographic analysis, an electrode clamp of high heat conductivity, comprising a water- 40 cooled iixed jaw mounted on an insulating support and having a plurality of electrode-engaging grooves of varying sizes, a water-cooled movable jawprovided with two rigidly attached guiding and supporting bars and also provided with corresponding electro-engaging grooves, a vyoke joining the outer ends of said bars, a compression spring within said yoke, aguiding and supporting channel for each bar 'of said movable jaw and a manually operated cam revolubly mounted in bearings in said bars for opening said jaws in opposition to said spring. i

4. The combination with an electrode holder for spectrographic analysis, of a two-part protecting housing opaque to rays injurious to eyes, vcomprising a relatively xed portion and a closure portion hinged to said first portion, an electric lamp mounted within the closure portion and supplied by a lighting circuit, a circuit closer for said circuit for completing said circuit when the housing is opened, a bar pivoted to one part of said housing and slidably connected with the companion housing portion, and a stop limiting the movement of sald'bar and housing to set said lamp in a predetermined optical path, whereby light may be directed at the electrodes vand through an opening in the rear of the housing to permit forming an image of the electrodes on a screen, and thus facilitate the adjustment of the electrode positions.

5. A sample holding accessory clamp for spectrographic analysis comprising an electrically conductive frame acting as a fixed supporting jaw for samples, a clamping jaw hinged to said drame, screw-operated means fortransmitting 75 force to said clamping jaw and an electrically assente conductive attaching stud secured to said frame and adapted to be detacnabiy engaged in a permanent electrode clamp.

6. An accessory clamp for rigidly and acc rately holding samples that cannot be accommodated in the usual electrode clamp for spectrographic analysis, comprising an electrically con ductiye U-shaped frame having facing inwardlyextending ilanges `forming a fixed two-part jaw against which the sample is clamped, a moyable jaw hinged to said frame, screw-operated means for transmitting force to said movable jaw, and electrically conductive studs extending from the bottom of said frame adapted to dea tachably engage in a permanent electrode clamp. 7. An accessory clamp of high heat conduc-s tivity `for holding samples that cannot be accontmodated in the usual electrode clamp for spec,- trographic analysis, comprising an electrically conductive iJ-shaped frame terminating in in- Hardly-extending ianges against which the sample is clamped, a clamping block ci hign neat conductivity, a movable jaw hinged to said isatne, screw-'operated means for transmitting force through said movable jaw to said block, and electrically conductive attaching studs extending irom the bottom of said frame adapted to de tachably engage the frame in a permanent electrode clamp, said frame ybeing rigidly and accurately held therein in the proper alignment for use.

An electrode for use in spectrographic analysis comprising a relatively permanent portion and a replaceable terminal portion provided with an axial recess for detachaloly mounting it noon said permanent portion, said terminal portion being provided with a specimen holding recesso Si. An electrode for use in spectrogiaphic analysis comprising the combination oi a supporting portion and a small replaceable terminal of carbon mounted upon said supporting portion, the monotoner consisting or" an aligning plug and `socket arrangement formed in the eespective pieces,

URDON FRANCS SQRBNER. @CHARLES HQWARD CGRMSS. 

